Concepts of Soil Formation and Soil Survey

Abstract

Soils are a product of the environment in which they form. The integrated effects of climate, organisms, initial parent material, and topography produce processes that, over time , differentiate soils that are characteristic of those combined environmental influences. Soil-forming processes include additions, most notably organic matter, and losses, such as dissolved ions that are leached from the soil to groundwater . Soils are also shaped by the processes of translocation, such as clay particles being moved to the subsoil by percolating water and transformation, as in the soil structural units created by shrink–swell activity. The imprint of the soil-forming factors and processes is reflected in the soils that occur on landscapes. The goal of soil survey is to model and record this imprint. The geographic pattern of soils is mapped by differentiating parts of the landscape that have experienced different combinations of soil-forming factors. Delineation with similar soils are grouped as a map unit for description and interpretation. The scale at which soils are identified and delineated depends on the intended land use. In the USA, soils are identified using the USDA Soil Taxonomy and soil survey information is available in hard copy reports and online.